A friend worked in a zoo. His duties were to clean up from time to time and feed the inhabitants. The animal consisted mostly of turtles and fish. Honestly, knowing the character of a friend, for nothing would allow him to such a responsible job as a nurse. He came there about once a week, feeding and leaving (where only the greens watched, and in the first place the management of the circle). Once he went in, filled food and went home, but at the last moment he felt a heavy look in his back. I turned, of course. I forgot to feed the piranha, who swam alone in a separate aquarium. From his words, he read in this view a silent reproach, the fish clearly understood that there would be no food for another week.